Intermittent-discharge grinding mill



June 18, 1929.- R.- H. WARREN 1,717,860

n INTERMITTENT DISCHARGE GRINDING MILL Original Filed Aug. 25, 1925ATTOR Y Patented `lune 18, 1929.

UNITED I STATES NPATENT OFFICE.

RALPH H. WARREN, OF NEW YORK, N. Y.; THE FARMERS LOAN AND TRUST COM-IPANY EXECUTOR OF SAID RALPH I-I. WARREN, DECEASEI).

INTERMITTENT-DISCIIARGE GRINDING MILL.

Application med August 25, 1925, serial No. 52,451. Renewed November 7,192s.

This invention relates to the trituration of v such substances as coal,cement and grain, and an important object of the invention is to pro;vide an improved process for eecting the reduction of coal to animpalpable powder suitable for combustion as a fuel, the processcomprising the step of subjecting the coal, preferably in agranularcondition, to the triturating action of preferablysmooth rotatingsurfaces, co-operating thereon in contiguous arv rangement, or soclosely adjacent to each other that the pulverulent coal issubstantially confined against escape normally; the rocess includingalso the recurrent Step of e] ectin the impalpable product, yat regularinterva s of `vtime, by separating the disks to, such a distance only asto permit such ejection therefrom of the impalpable portion of the coalby centrifugal force. i

A furtherobject of the invention is to provide a compact and inexpensivemachine for carrying the process into effect for the trituration of coaland the like, and to provide such a 4machine with means, preferably of amagnetic character, such as an electrical solenoid, to produce therequired intermittent separation of the metal disks which constitute thepreferred form of triturating device, and ,thereby to effect theejection of the impalpable product, and the progressive advancement ofthe granular supply, concurrently.

Still another objectof theinvention is to provide an organized machinehaving a plurality of sets of triturating disks in couples, of which onedisk in each set is mountedto` rotate upon `,a shaft common to -bothsets,

While the other disk of each set is provided With means to effect itsintermittent operation axially to permit ejectment centrifugally Yof thepulverulent product.

The above process, andthe novel machine herein disclosed as a nowpreferred apparatus for eflicient utilization of the process, achieve anunusualreiinement of trituration, with a rapidity in the productiono'flarge quantities of powdered fuel or other materials which has beenregarded heretofore as impracticable, whereby substantial economies inthe cost thereof are effected.

The various features of the invention Will be illustrated and describedfully in the accompanying drawings and specification and .pointedout inthe claims.)

In the drawings,

Fig. 1 isa View in front elevation of a triturating machine adapted tocarry into effect the novel process of this application, and whichembodies novel structural features constituting part of the invention.

Fig. '2 is a vievs7 on a smallerscale of a modi- Vfiedform of similarapparatus characterized by a plurality of sets of similar -trituratingcouples with appropriate controlling devices, this view omitting some ofthestructural details shown in Fig. 1. I

In the illustrated embodiment is shown a couple of co-operating disksnumbered 1 and 2, in superimposed relation, the lower disk being carriedrotatably by a vertical shaft 3 mounted in bearings L1 supported by abase 5 on any suitable foundation, and Ihave shown means for actuatingthe shaft 3 taking the form of a driving shaft 6 running 'from asuitable source of power, not shown, to a bevell gear 7 engaged With abevel gear 8 on the vertical shaft 3. i

By such means the disk 1 is rotatedcontinuously relatively to the disk2, which is preferably non-rotatable but is adapted to move along theaxis of rotation of the disk 1 to bring normally into proximity thetriturating surfaces 9 and 10, Which occupy a peripheral annular regionin which the surfaces 9 and 10 are approximately.contiguous, or soclosely adjacent to each other as to confine the material undertreatment, which is fed thereto at the centre'of the disk 2, Where theWorking surface is preferably dished somewhat, as indicated at 12, tofacilitate gradual reduction of the larger granules of material. l i yThis dished portion 12 of the Working surface, as Well as the annularportion 9 and the co-operating portions 11 and 10 of the rotary disk 1,arepreferably smooth or but slightly roughened, and accordingly requirebut little attention, andthe feeding arrangements are preferably of asimple character, involvinga minimum cost for upkeep. As a suitablestructure for feeding the material, an axially disposed throat 13 shown,Which leads .from anoverhead feed hopper 14 and is fixed at 15 Withinthe central aperture of the disk 2, the material of the throat beingdesirably of soft iron, and its dimensions such as to constitute it amagazine of considerable capacity. Y

The Weight of the disk 2, 'throat 13, and their associated parts. withthe Weight of the material `.cOII'itained '.fthere'in, is such as tomaintain a. Very effective grinding pressure on the material, and thevertical aligmnent of the unitary structure thus constituted ismaintained by suitable bearings 16 and 17 carried by cross-beams 18 and19 bolted to the frame uprights 20, rotative movement of the throat 13and disk 2 being prevented by a gib 21.

In pursuance of the invention, means are provided to cause recurrentseparation of the disks 1 and 2 intermittently during operative rotationof the disk 1, for the purpose of releasing theimpalpable or relativelyrefined product for ejectment by centrifugal force, while the coarsergranules are left under confinement for further treatment, the effectbeing to distchargethe impalpable product peripherally from between theannular surfaces 9 and 10 into a suitable hopper 22 with a dischargespout 23, while the coarser granules centrally disposed within the mouth24 of the feed throat 13, and within the dished portion 12 of the upperdisk 2, are advanced by gravity and centrifugal force into the momentarily enlarged annular space between theA surface portions 9 and 10 justvacated by ejectment of the impalpable product therefrom. n

Any suitable Imeans, mechanical or electrical, may be provided to effectthe oscillation of the disk 2 requisite to perform this step in theprocess or trituration, and as a now preferred form of means to thisend, the machine is illustrated as having an electrical magnet in theform of an electrical coil or solenoid 25 supported in a bearing 26 upona cross-beam27 bolted to the frame members 20, and energized by asuitable source of current indicated conventionally, at 28, as abattery,

included in an electrical circuit comprising conductors ,29, a switch 30and a commutator 31, the latter being of well-known construction and notrequiring detailed description, except to note thatit is operated fromthe shaft3 through a train of reductionsgearing 32, and the frequency ofthe oscillations of the disk 2 is determined by the turns per minute ofthe contact segment 33 in engagement electrically with the contactfinger 34, the duration of each separation being governed by the size ofthe segment 33.

It is preferable ordinarily to permit only a momentary separation of thedisks 1 and 2 for evacuation and recharging of the annular space betweensurfaces 9 and 10, inasmuch as otherwise material will be discharged inpartially ground condition. i The throat 13 may be provided with a softiron core or armature 35, if desired, to facilitate the magnetic action,and an adjustable stop-collar 36 may also be supplied to limit theuplift of the disk 2.

In the structure shown in Fig. 2, two sets of triturating couples areillustrated,`each comprising a rotating disk, 41, and a nonrotatingdiskv42, the two disks 41 being keyed to a common driving shaft 43,while the disks 42 are each subject to the oscillative actuation of anindependent electric solenoid 45 operating in the manner alreadydescribed to separate the disks 42 from the disks 41, the use ofindividual solenoids having the advantage of convenient simplicity ofstructure while permitting independent variation of the ejectment ofproduct to correspond with the degree of refinement to be attained byone unit of the apparatus or the other.

Accordingly, theupper couple of disks 41 and 42 may be supplied withrelatively coarse material through a hopper 14 and throat 13, like thosealready described, and operated with the solenoid 45 acting to produce aiven refinement of trituration; the product eing discharged to a'hopper44 and by it delivered tothe throat 53of the lower couple, and treatmentmay be there continued to produce an impalpable product, by properyregulation of the operation of the lower solenoid 45, and the finalproduct will be discharged peripherally into the hopper 66. Suitablesupporting structure for this system of triturating devices will beprovided, as indicated fragmentarily at 55.

Having described and illustrated the inwhich the process may be carriedinto effect, it is to be understood that the invention is not limited tothe specific materials, structural details or sequence of operationsselected for illustration and description,l nor in general isV itlimited otherwise than as set forth in the claims read in connectionwith this specification.

What I claim and desire to secure by Letters Patent is:

1. Triturating apparatus comprising a pair of superimposed disks havingopposed i smooth working surfaces arranged co-axially, `the lower diskbeing rotatable relatively to the other disk; meansto rotate saidlowerdisk; means to maintain the upper disk in `axial, alignmentwhilepermitting co-axial kmovement thereof; and means to cause saidreciprocatory movement intermittently during continued rotation of saidlower disk, said means comprising a magnet coil arranged .to lift saidupper disk when energized; and an elect-rica] circuit-including a sourceof electrical current `toenergize said magnet coil, andcircuit-controlling means to regulate theperiods of reciprocatorymovement. i

2. Apparatus for triturating granular materials, said apparatuscomprising a plurality ofsets of disks, each set comprising a coul pleof disks co-operating in axial alignment and one of which is rotatableand the other adapted to reciprocate axiallyrelatively to itsco-operating disk; means to rotate said rotatable disks; and means tocause said reciproeation of said axially movable disks, saidreciprocation-eausing means comprising a plurality of independent magnetcoils acting upon said axially movable disks respectively.

3. Apparatus for triturating granular ma.- terials, said apparatuscomprising a plurality oit sets of disks, eac-l1 set comprising a coupleof disks co-operating in axial alignment, and one of Which is rotatableand the other adapted to reciprocate axially relatively to its(fo-operating disk; means to rotate said rotatable disks; and means tocause said reciproeation of said axially movable disks, saidreciprocation-causing means comprising a plurality of independent magnetcoils aoting upon said axially movable disks respectively and saidrotating means comprising a rotatable shaft connected operatively Withsaid rotatable disks respectively.

Signed at New York, in the county and State of New York, this 15th dayof June, 1925.

RALPH H. VARREN.

